Conventionally, touch switches have been widely known which detect a human body part touching on or approaching to a conductive electrode member and trigger a desired instrument. In such touch switches, the electrode member functions as a capacitance sensor which detects on-off of the touch switch by reading change in impedance (capacitance) of the electrode when a human body touches the electrode.
Examples of such a capacitance type touch switch include: one in which an electrode, a connection pattern (wiring portion), a conductive thin film and the like are formed by spattering in the form of films (for example, refer to Patent Document 1); and one in which an electrode, a connection pattern, a conductive thin film and the like are formed on a base material by screen printing with a conductive ink.
Such touch switches can be used for automotive instrument panels. Specifically, they can be used as automotive switches such as on-off switches of audio systems or air conditioners, and selector switches switching between various modes. In such cases, if the electrode member is formed on a light-transmissible base material, the switch can be light-transmissible itself while the light is lit and thus enhances the viewability thereof, which maintains the usability even in the nighttime.
[Patent Document 1] Japanese Patent Laid-Open Publication (Kokai) No. 2005-38739